The document summarizes key aspects of the human circulatory system. It explains that the circulatory system has three main components: fluid (blood), blood vessels (arteries, veins, capillaries), and the heart. It transports gases, nutrients, wastes, and hormones. It notes that humans have a double circulatory system with two loops - the pulmonary system and systemic circulatory system. The pulmonary system carries deoxygenated blood to the lungs and oxygenated blood back to the heart, while the systemic system circulates blood to and from the body's tissues and organs.

1. “what we know , what we think we know & what we don’t know.”
QUIZ

2. 2
“what we know , what we think we know & what we don’t know.”
1. What are the main functions of the circulatory system?
2. Circulatory systems generally have three main features.
Name these.
3. Name the three major classes of blood vessels.
components

3. 3
“what we know , what we think we know & what we don’t know.”
1. What are the main functions of the circulatory system?
Transporting gases, nutrients, wastes & hormones
2. Circulatory systems generally have three main features. Name these.
Fluid, Blood vessels & Heart
3. Name the three major classes of blood vessels.
Arteries
Veins
Capillaries

4. 4
“what we know , what we think we know & what we don’t know.”
4. What is always true of arteries?
Always carry oxygenated blood.
Always carry deoxygenated blood.
Always carry blood away from the heart.
Always carry blood to the heart.
Always carry oxygenated blood.

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“what we know , what we think we know & what we don’t know.”
5. Why are capillary walls so thin?
Because capillaries are thin & narrow.
To allow exchange of gases & nutrients.
All of the above.
To force RBCs to move through in single file.

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“what we know , what we think we know & what we don’t know.”
N2
Traffic in Cape Town …
Cape Town
People

7. 7
“what we know , what we think we know & what we don’t know.”
N2
Cape Town
People
N1
Traffic in Cape Town …

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“what we know , what we think we know & what we don’t know.”
Circulatory system vs Traffic in Cape Town?
• COMPONENTS: Fluid, Blood vessels & Heart
• FUNCTIONS: Transport gases, nutrients,
wastes & hormones
• we have a double circulatory system
– it has TWO parts
Cape Town = Heart
People = Fluid
N1 & N2 = Blood vessels
N2
Cape Town
People
N1

9. body cells
lungs
Cape Town = Heart
People = Fluid
N1 & N2 = Blood vesselsN2
Cape Town
People
N1
CIRCULATORY SYSTEM
• COMPONENTS: Fluid, Blood vessels & Heart
• FUNCTIONS: Transport gases, nutrients, wastes & hormones
• we have a double circulatory system – it has TWO parts

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“what we know , what we think we know & what we don’t know.”
Circulatory system
 COMPONENTS: Fluid, Blood vessels & Heart
 FUNCTIONS: Transport gases, nutrients, wastes & hormones
 we have a double circulatory system – it has TWO parts

11. lungs
right left
Right hand side:
DEOXYGENATED
blood
Left hand side:
OXYGENATED
blood
body cells
(O2-poor)
(O2-rich)
Circulatory system

12. 12
“what we know , what we think we know & what we don’t know.”
 COMPONENTS: Fluid, Blood vessels & Heart
 FUNCTIONS: Transport gases, nutrients, wastes & hormones
 we have a double circulatory system – it has TWO parts
 Right hand side: DEOXYGENATED blood (O2-poor)
 Left hand side: OXYGENATED blood (O2-rich)
Circulatory system

13. Right hand side: DEOXYGENATED blood (O2-poor)
Left hand side: OXYGENATED blood (O2-rich)
Circulatory system
VEINS
towards
ARTERIES
away

14. 14
“what we know , what we think we know & what we don’t know.”
 COMPONENTS: Fluid, Blood vessels & Heart
 FUNCTIONS: Transport gases, nutrients, wastes & hormones
 we have a double circulatory system – it has TWO parts
 Right hand side: DEOXYGENATED blood (O2-poor)
 Left hand side: OXYGENATED blood (O2-rich)
 ARTERIES – carries blood AWAY from the heart
 VEINS – carries blood TOWARDS the heart
Circulatory system

15. Circulatory system
VEINS
towards
ARTERIES
away
• Pulmonary Artery
– carries DEOXYGENATED blood away from
the heart
• Pulmonary vein
– carries OXYGENATED blood towards
the heart
Right hand side: DEOXYGENATED blood (O2-poor)
Left hand side: OXYGENATED blood (O2-rich)

16. 16
“what we know , what we think we know & what we don’t know.”
 COMPONENTS: Fluid, Blood vessels & Heart
 FUNCTIONS: Transport gases, nutrients, wastes & hormones
 we have a double circulatory system – it has TWO parts
 Right hand side: DEOXYGENATED blood (O2-poor)
 Left hand side: OXYGENATED blood (O2-rich)
 ARTERIES – carries blood AWAY from the heart
 VEINS – carries blood TOWARDS the heart
 pulmonary artery carries deoxygenated blood away from the heart
 pulmonary vein carries oxygenated blood towards the heart
Circulatory system

17. PULMONARY circulatory system
SYSTEMIC circulatory system
Circulatory system
CORONARY circulatory system
• carries blood around to & from the lungs
• provides heart with blood
• carries blood around the body

18. Circulatory system head & arms
lungs
digestive system
kidneys
lungs
liver
legs
PULMONARY
circulatory
system
SYSTEMIC
circulatory
system

19. 19
“what we know , what we think we know & what we don’t know.”
 COMPONENTS: Fluid, Blood vessels & Heart
 FUNCTIONS: Transport gases, nutrients, wastes & hormones
 we have a double circulatory system – it has TWO parts
 Right hand side: DEOXYGENATED blood (O2-poor)
 Left hand side: OXYGENATED blood (O2-rich)
 ARTERIES – carries blood AWAY from the heart (except the pulmonary artery)
 VEINS – carries blood TOWARDS the heart (except the pulmonary vein)
 Pulmonary system & Systemic circulatory system
Circulatory system

20. head & arms
lungs
lungs
liver digestive system
kidneys
legs
Circulatory system
PULMONARY
circulatory
system
SYSTEMIC
circulatory
system

21. 21
“what we know , what we think we know & what we don’t know.”
precapillary sphincters
ARTERY
capillary bed
arteriole
VEIN
venule
muscular
layer
Circulatory system

22. 22
“what we know , what we think we know & what we don’t know.”
artery vein
body cell
• body tissues contain a vast network of thin capillaries
• capillary walls are only one cell thick
– allowing exchange of gases, nutrients & wastes
capillaries
Circulatory system

23. 23
“what we know , what we think we know & what we don’t know.”
VEINSARTERIES
away towards
BODY CELL
Circulatory system

24. 24
“what we know , what we think we know & what we don’t know.”
 COMPONENTS: Fluid, Blood vessels & Heart
 FUNCTIONS: Transport gases, nutrients, wastes & hormones
 we have a double circulatory system – it has TWO parts
 Right hand side: DEOXYGENATED blood (O2-poor)
 Left hand side: OXYGENATED blood (O2-rich)
 ARTERIES – carries blood AWAY from the heart (except the pulmonary artery)
 VEINS – carries blood TOWARDS the heart (except the pulmonary vein)
 Pulmonary system & Systemic circulatory system
 Blood vessels: Arteries – Capillaries – Veins
Circulatory system

25. 25
“what we know , what we think we know & what we don’t know.”
 COMPONENTS: Fluid, Blood vessels & Heart
 FUNCTIONS: Transport gases, nutrients, wastes & hormones
 we have a double circulatory system – it has TWO parts
 Right hand side: DEOXYGENATED blood (O2-poor)
 Left hand side: OXYGENATED blood (O2-rich)
 ARTERIES – carries blood AWAY from the heart (except the pulmonary artery)
 VEINS – carries blood TOWARDS the heart (except the pulmonary vein)
 Pulmonary system & Systemic circulatory system
 Blood vessels: Arteries – Capillaries – Veins
Circulatory system